Hi Xiyu,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on vhost/linux-next]
[also build test WARNING on v5.14-rc1 next-20210716]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Xiyu-Yang/vhost_net-Convert-from-atomic_t-to-refcount_t-on-vhost_net_ubuf_ref-refcount/20210718-101502
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
config: arm64-randconfig-r021-20210718 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 5d5b08761f944d5b9822d582378333cc4b36a0a7)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # https://github.com/0day-ci/linux/commit/8aaf246d79e6bb03b71d9a1a13289f919aa34215
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Xiyu-Yang/vhost_net-Convert-from-atomic_t-to-refcount_t-on-vhost_net_ubuf_ref-refcount/20210718-101502
        git checkout 8aaf246d79e6bb03b71d9a1a13289f919aa34215
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <redacted>

All warnings (new ones prefixed by >>):

quoted

drivers/vhost/net.c:253:6: warning: ISO C90 forbids mixing declarations and code [-Wdeclaration-after-statement]

           int r = refcount_read(&ubufs->refcount);
               ^
   1 warning generated.


vim +253 drivers/vhost/net.c

   249	
   250	static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs)
   251	{
   252		refcount_dec(&ubufs->refcount);
 > 253		int r = refcount_read(&ubufs->refcount);
   254		if (unlikely(!r))
   255			wake_up(&ubufs->wait);
   256		return r;
   257	}
   258	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org